Date Added: Nov 2012
In location-based, mobile Continual Query (CQ) systems, two key measures of Quality-of-Service (QoS) are: freshness and accuracy. To achieve freshness, the CQ server must perform frequent query reevaluations. To attain accuracy, the CQ server must receive and process frequent position updates from the mobile nodes. However, it is often difficult to obtain fresh and accurate CQ results simultaneously, due to limited resources in computing and communication and fast-changing load conditions caused by continuous mobile node movement.